Answers
What should you do if somebody is threatening you online?
Screenshot it, block them, and report it — in that order, because blocking can remove your access to the evidence. If the threat is credible and immediate, contact the police; a platform report is not an emergency service.
Preserving the record first is the step people skip. Once somebody is blocked, the conversation may no longer be reachable, and a report is stronger with specifics.
Blocking is the control that works immediately and needs nobody's agreement. It should not wait on a report being reviewed.
On Naven, credible threats of violence are one of the twelve screened categories, so many never arrive. Report sits next to Block in the conversation menu, and a person reads what is sent.